Rule 820.1.d

Repeat is functionally short for “You may pay [Cost] as an additional cost as you play this. If you do, execute the instructions of this chain item one additional time during resolution.”

• 820.1.d.1 When the additional cost is paid, the effect of the spell or ability, upon resolution, will be performed an additional…
• 820.1.d.2 Any instructions not performed on resolution of the spell or ability are ignored.

Official Core Rules